The fountains of the U.S. Navy Memorial are annually salted with water from the Seven Seas as part of a nautical ritual.

Helen Keller once broke ground on this historic center for the study of technologies to benefit the hearing impaired.

There's an old indoor swimming pool hidden directly underneath the White House Press Briefing Room.

Washington's top-secret Cold War-era doomsday communications tower is located in a small neighborhood park.

The only National Monument ever to go missing for nearly 50 years then resurface in a dump.

A historic arena where the Beatles played their first concert in the U.S.

Architecture lovers won’t stop touching the National Gallery's 19.5 degree marble prow.

The discovery site of the "Capitalsaurus," the official dinosaur of Washington, D.C.

Washington's iconic carousel has a nice piece of Civil Rights history.

A fantastic array of trays and cables once whisked books over to the Capitol at 600 feet per minute.

The towering figures were created from the cemetery's fallen old-growth trees.

This poor little statue is the most vandalized memorial in Washington.

In the basement of the U.S. Capitol Building is a hidden storage room full of ornate floor tiles leftover from the 1850s.

The span is crooked and made from two older recycled bridges.

An easily overlooked memorial to a Ukrainian famine-genocide that killed over 4 million people.

A little marble compass above George Washington's (empty) tomb in the Capitol marks where D.C.'s four quadrants intersect.

The institution is sitting on a goldmine of 21,000 paints, varnishes, pigments, and primers preserved for posterity.

The remains of Martha, the last known passenger pigeon, serve as a tool to educate about conservation.

This lovely pocket park is one of the most under appreciated in D.C.

Light bulbs, scrap wood, and tinfoil comprise this homemade throne of the gods.

A traveling postal dog covered 48 states and more than 140,000 miles, and he lives on as taxidermy, patched up with a rabbit's foot and a pig's ear.

Perhaps the most scandalous statue of America's first president.

A hoard of sky catalogs, astrophysical journals, even the works of Galileo and Copernicus.

Decades before the scandal, this staircase on the river was a literal "water gate."